Eraser



Oct. 5, 1943. A. C'QTERA 2,330,954

ERAS ER Filed Nov 27, 1941 1: 1 m nae.

INVENTOR.

fluaasfus 5 0075/54 A T TORNE Y.

Patented Oct. 5, 1943 ERASER I AIag tstus'iS.v Cetera,Galvestom Texassignor' to; N

Charles Brunin'g Company, Inc., New York;

N. Y., acorporation of New York I Application November 27, 1941';SerialN'o. 420,633

scams; (Gino-+4.0.)

The present invention relates to erasers and,

more specifically, to the structureofthematerial' which like. a

The usual form 'oferaser utilized in erasing machines -isthe cylindrical-eraser'or eraser in which the erasing material is formed in the shapeof a cylinder, the cylindrical surface of which is smooth. Althougherasers have been used having cross-sections other than cylindrical,

is used in erasingmachines'and-the the surface of these erasers hasalways been smooth.

In accordance with the present invention, it is an object to provide aneraser having a structure such that the erasing operation will beaccomplished more effectively and more quickly than has beenaccomplished with the structures heretofore available.

The foregoing object is attained by providing a structure wherein thesurface of the eraser is formed with depressions in the form either ofgrooves or pits which thus disturb or break up the regularity andsmoothness of the outer surface of the eraser. The essential feature ofthe present invention is the provision of the eraser surface withre-entrant portions, the design or configuration of which isunimportant, the important factor being that these configurations lie inthe side surface of the eraser.

In order that the invention may be understood more fully, it will bedescribed now with reference to the accompanying drawing, wherein:

Fig. 1 is a View in side elevation of an eraser formed in accordancewith the present invention.

Fig. 2 is a View in end elevation showing the eraser of Fig. 1.

Fig. 3 is a view similar to Fig. 1, showing a modified form of eraser inwhich the cylindrical surface is formed with a plurality of pits orrecesses.

Fig. 4 is a view in end elevation, showing the eraser of Fig. 3.

Fig. 5 is a view similar to Fig. 1, showing a further modified form ofthe invention in which the cylindrical surface of the eraser is formedwith spiral grooves.

Fig. 6 is a view in end elevation, showing the eraser of Fig. 5.

Fig. '7 is a view similar to Fig. 1, showing a further modified form ofthe invention.

Fig. 8 is a view in end elevation, showing'the eraser of Fig. 7.

Referring to the above drawing and particularly to Figs. 1 and 2,aneraser I0'formed of rubber or the like is provided with a cylindricalsurface 41 n which aplu'r'ality of longitudinally extending grooves ornotches I 2are formed; In

accordance with the general practice," the eraser is made of rubber and.the groo'vesimay be of varying depth and width in order that the.erasing end of'the'eraser'may-be'formed with notches or irregularitiessuch'as illustrated in Fig. 2. It has been found that the eraser formedin this fashion is far more effective in performing erasing operae tionsthan the identical eraser would be if it were formed with a cylindricalsurface of uniform and smooth cylindrical nature.

A modified form of the invention is shown in Figs. 3 and 4, wherein thecylindrical surface H of the eraser I0 is formed with a plurality ofpits I3. These pits are preferably formed in sufiioient number andlocation such that, at any one time,'the Working surface and edge of theeraser will always be formed with a plurality of irregularitiesresulting from the pits as illustrated in Fig. 4.

In the form of the invention shown in Figs. 5

and 6, the eraser H] is provided with a cylindrical surface Hhaving'spiral grooves I4 formed therein in sufficient number'to'providea plurality of notches at the edge of the working surface of the eraser.

In the modification of the invention shown in Figs. 7 and 8, the eraseris formed of hexagonal cross-section in order that a plurality of sharpcorners 15 may be provided. 'I'heedges formed by these corners providefor an operation that is found to be far more effective than theconventional eraser of round cross-section.

It is to be understood that the eraser described hereinabove is in theform of an elongated member that is adapted to be mounted in a rotatingchuck, the structure being such that th erasing end or surface rotatesabout the axis of the eraser as it is brought into erasing relationshipwith the surface to be erased. In accordanc with the.

present invention, the erasing properties of the device are greatlyimproved by providing surface irregularities or conformations on thesides of the eraser that interrupt or disturb the circular shape of theerasing surface or end of the eraser.

It will be readily apparent that the invention may be embodied inerasers by forming in the side surfaces thereof irregularities of manyshapes and sizes other than those illustrated in the drawing as abovereferred to. quirement of the invention is that the side surface of theeraser be formed with a surface having irregularities such thatre-entrant portions are available in the side surface to provide irregu-The essential relarities or recesses in the edge of the working surfaceat the end of the eraser.

While the invention has been described with reference to the specificeraser structure shown in the accompanying drawing, it is not to belimited save as defined in the appended claims.

I claim: 7 r

1. An eraser for an erasing machine having a rotatable chuck, comprisingan elongated solid body of erasing material having one end portion to bereceived in said chuck with the remainder of said body coaxial with saidchuck and its opposite end free for application to the work to beerased, said opposite end and said remainder of said body beingnon-circular in cross-section and v symmetrical about the lon itudinalaxis of said body and presenting an external surface with a plurality ofreentrant portions extending at an, angle to the direction in which theeraser is ro to be received in said chuck with the remainder of saidbody coaxial with said chuck and its opposit'e end free for applicationto the work to be erased, said remainder of said body being ofsubstantially cylindrical shape and having a plurality of substantiallyequally spaced external grooves extending lengthwise thereof to saidopposite end whereby rotation of said eraser by the chuck serves toexert a plurality of successive erasing actions on the surface which itengages during each revolution of the eraser.

3. An eraser for an erasing machine having a rotatable chuck, comprisingan elongated, solid body of erasing material having one end portion tobe received in said chuck with the remainder of said body coaxial withsaid chuck and its opposite end free for application to the work to beerased, said remainder of said body being of substantially cylindricalshape and having a plurality of substantially equally spaced groovesextending helically around the exterior thereof to said opposite endwhereby rotation of said eraser by the chuck serves to exert a pluralityof successive erasing actions on the surface which it

